Original Scientific ArticleMac Vet Rev 2016; 39 (1): [51][52][53][54][55][56][57] Thirty California female rabbits were obtained from the Animal Care Center, College of Agriculture, South Valley University and acclimated to laboratory conditions for one week. The Leiurus quinquestriatus (LQ) venom was collected from mature scorpions by electrical stimulation of the telson. A single dose of crude venom of 0.4 ml/kg (diluted in normal saline with a ratio of 1:1) was injected into a peripheral ear vein. The lungs, brains, hearts, kidneys, were sampled and fixed in 10% formalin from rabbits sacrificed at zero, 30 minutes, 1hr, and 4hrs, post-envenomation (three animals at each sacrifice). Respiratory distress and neurological manifestations were the main clinical signs. Congestion of the lungs was started at one hour postenvenomation. Vascular changes including hyperemia and hemorrhage were also observed till 24 hours post-envenomation. The main histopathological changes of the lungs were edema, hemorrhage, emphysema, and eosinophilic bronchitis. Transmission electron microscopy revealed several eosinophils with abundant granules and breakdown of their membranes suggesting degranulation. The cerebrum showed malacia and edema. Myocardial damage expressed by focal area of myolysis at half-hour post-envenomation and interstitial edema by at 1, and 4 hour post-envenomation was also evident. In conclusion, scorpion venom induced consistent and relevant histopathological changes in all examined organs.